TWI499661B - A liquid crystal compound having difluoro-vinyl diether-based structure, a liquid crystal composition comprising said compound and applicaton thereof - Google Patents

Description

a liquid crystal compound containing a difluorovinyl diether structure, including the same Liquid crystal composition and liquid crystal display

The present invention relates to a liquid crystal compound, and a liquid crystal composition comprising the liquid crystal compound, and more particularly, to a novel liquid crystal compound containing a difluorovinyl diether structure, and a liquid crystal comprising the same A liquid crystal composition of the compound.

Physically, the matter is divided into three states, namely solid, liquid and gaseous. In nature, most materials exhibit only three states of solid state, liquid state and gas state with temperature. Liquid crystal is a new material state different from the usual solid, liquid and gaseous states. The liquid crystal can be in a certain temperature range. The state of matter in which both the liquid and the crystal are characteristic, also referred to as the liquid crystal phase or the intermediate phase, is also referred to as the fourth state of matter.

There are many types of liquid crystals, and there are thousands of naturally occurring and synthetic liquid crystals, but they are basically organic compounds. According to the conditions formed by the liquid crystal phase, the liquid crystal can be divided into a thermotropic liquid crystal and a lyotropic liquid. Crystal, inductive liquid crystal and flow-through liquid crystal.

Currently, liquid crystal materials for display are basically thermotropic liquid crystals. Thermotropic liquid crystals can be classified into smectic liquid crystals (Smectic, also known as smectic liquid crystals), nematic liquid crystals (Nematic, also known as filamentous liquid crystals), and cholesterol phase liquid crystals (Cholesteric). It is called spiral liquid crystal). The physical properties of these phases are known. Molecular structural features of liquid crystal compounds used in the field of optoelectronics generally have a rigid backbone comprising, for example, successive 1,4-phenylene or 1,4-cyclohexylene or heterocyclic ring systems which are as far apart from each other as possible It is substituted by a terminal group such as an alkyl group, an alkoxy group or a cyano group.

The liquid crystal composition used in the field of optoelectronics is composed of a mixture of these compounds, and a compound which does not have a mutual transformation from a crystal phase to a liquid crystal is also used therein. Classified by liquid crystal display, liquid crystal compositions can be classified into dynamic scattering type (DS type), guest main type (GH type), twisted nematic type (TN type), super twisted nematic type (STN type), thin film transistor type. (TFT type) and ferroelectric type (FLC type). Liquid crystal materials have been widely used in the production of liquid crystal display elements such as tablet computers, various measuring instruments, automotive instrument panels, notebook computers, mobile phones, computers, and televisions.

Heretofore, various liquid crystal materials have been synthesized into a plurality of compounds, which can be used depending on the manner of display or the manner of driving and the use thereof. On the other hand, the demand for improving the performance of liquid crystal display elements has been increasing year by year, and in order to meet this demand, it is necessary to continue to develop novel liquid crystal compounds.

It is an object of the present invention to provide a novel liquid crystal compound containing a difluorovinyl diether structure.

Thus, the novel liquid crystal compound of the present invention containing a difluorovinyl diether structure has the structure of the general formula (I):

Wherein R ₁ and R ₂ are the same or different and each independently represents -H, -F, -Cl, -CN, -NCS, -SCN, -OCN, -NCO, a linear or branched alkyl or alkoxy group having 1 to 20 carbon atoms substituted or unsubstituted with at least one halogen, a linear chain having 2 to 20 carbon atoms substituted or unsubstituted with at least one halogen Or a branched alkenyl or alkenyloxy group, wherein at least one of _-1 -CH ₂ - in R ₁ and R ₂ may be independently independently taken up by -O-, -S-, -SiH ₂ -, -CH=CH -, -C≡C-, -CF=CF-, -CH=CF-, , -COO- or -OCO-substitution, provided that the heteroatoms are not directly connected to each other; the rings A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ are the same or different and each independently represents , , , , , , or Ring structure; alternatively, the ring structure further conforms to at least one of (a), (b), (c), and (d): (a) one or more hydrogens in the ring structure The atoms may each independently be -D, -F, -Cl, -CN, -CF ₃ , -OCF ₃ , -CH ₂ F, -OCH ₂ F, -CF ₂ H, -OCF ₂ H, -OCH ₃ or -CH ₃ substituted; (b) one or more -CH ₂ - in the cyclic structure may be independently substituted by -O-, -SiH ₂ -, -S- or -CO-, provided that the heteroatoms are not Directly linked; (c) in the cyclic structure, one or more -CH- in the aromatic ring structure may each be independently substituted by N; (d) one or more of the cyclic structures Can be independently Substituted; Z ₁ , Z ₃ , Z ₄ and Z ₅ are the same or different and each independently represents a single bond, -COO-, -CF ₂ O-, -CH ₂ O-, -OCH ₂ -, -CH ₂ CH ₂ -, -CF ₂ CH ₂ -, -CF=CF-, -CH=CH-, -CH=CF-, -C ₂ F ₄ -, -(CH ₂ ) ₄ -, -(CF ₂ ) ₄ - , -OCF ₂ CF ₂ O-, -CF ₂ CF ₂ CF ₂ O-, -CH ₂ CH ₂ CF ₂ O-, -OCH ₂ CF ₂ O-, -CH ₂ CF ₂ OCH ₂ -, -CH=CHCF ₂ O-, -CF ₂ OCH=CH-, -CF ₂ OCF=CH-, -CF ₂ OCH=CF-, -CF=CFCF ₂ O-, -CF ₂ OCF=CF-, -CH=CHCH ₂ CH ₂ -, -CH ₂ CH=CHCH ₂ -, -C ₂ H ₄ OCH ₂ -, -OCH ₂ CH ₂ CH ₂ -, -CF=CF=CF=CF-, -C≡C-CF=CF-, -C≡C-CF=CF-C≡C-, -C≡C-, -CF=CF-C≡C-CF=CF- or -C≡C-CF ₂ O-; a represents 0 or 1, b, c and d are the same or different, and each independently represents 0, 1 or 2, when b is 2, two Z ₃ and two A ₄ are each the same or different; when c is 2, two Z ₄ And two A ₅ are each the same or different; when d is 2, two Z ₅ and two A ₆ are the same or different.

Another object of the present invention is to provide a synthesis method for synthesizing the liquid crystal compound of the formula (I).

Thus, the synthesis method of the present invention for synthesizing the liquid crystal compound of the formula (I) comprises the steps of: forming a sodium salt of the compound of the formula (III-2) and sodium hydride, and reacting with tetrafluorodibromoethane to obtain a formula ( III-1) A compound of the formula (III-1) is reduced by lithium aluminum hydride to give a compound of the formula (III).

The compound of the formula (III) and sodium hydride form a sodium salt, and then with the formula (IV) The compound is reacted to give a compound of the formula (I).

The compound of the formula (III-2) and the compound of the formula (III) are mainly synthesized by a commercially available intermediate or a known synthesis method, wherein the known synthesis methods include esterification, Wittig reaction, carbon-carbon. A cross-coupling reaction (for example, Suzuki coupling, Negishi coupling, Heck coupling, Sonogashira coupling or transition metal catalyzed Grignard reagent cross-coupling reaction, etc.) or a reduction reaction or the like is obtained.

The main reaction process is as follows:

(1). In the anhydrous dimethylformamide solvent, under the argon atmosphere, add the compound of the formula (III-2), add sodium hydride in portions, heat to 60 ° C for 1 hour, cool to room temperature (25 After ±3 ° C), a solution of ethyl fluoroacetate in dimethylformamide was added dropwise thereto, and the mixture was reacted at room temperature (25 ± 3 ° C) for 12 hours to obtain a compound of the formula (III-1).

(2) The compound of the formula (III-1) is dissolved in anhydrous acetonitrile, and zinc powder is added under a nitrogen atmosphere, and refluxed for 10 to 12 hours to obtain a compound of the formula (III).

(3) The compound of the formula (IV) is dissolved in an anhydrous dimethylformamide solvent, sodium hydride is added under a nitrogen atmosphere, the temperature is raised to 60 ° C for 1 hour, the compound of the formula (III) is added, and the reaction is carried out at 60 ° C for 1 hour. A liquid crystal compound of the formula (I) is obtained.

It is still another object of the present invention to provide a liquid crystal composition comprising the liquid crystal compound of the formula (I).

Thus, the liquid crystal composition of the present invention contains at least one liquid crystal compound of the formula (I).

A further object of the present invention is to provide a liquid crystal composition for use in a liquid crystal cell, which can be used for a liquid crystal cell containing a liquid crystal medium such as TN, STN, TFT, VA, ECB, OCB, LCP, PDLC, BiNem, LC LENS. Display mode liquid crystal elements such as FFS and IPS.

Thus, the liquid crystal display of the present invention comprises a liquid crystal composition as described above.

The effect of the present invention is that the novel liquid crystal compound containing a difluorovinyl diether structure [i.e., a liquid crystal compound of the formula (I)] has good chemical and physical properties and has a lower viscosity than other liquid crystal materials, and is larger. Optical anisotropy and large dielectric anisotropy.

The present invention will be described in detail below. Preferably, R ₁ and R ₂ are the same or different and each independently represents H, -F, -Cl, -CN, -NCS, a linear or branched alkyl or alkoxy group having 1 to 10 carbon atoms substituted or unsubstituted with at least one halogen, a linear chain having 2 to 10 carbon atoms substituted or unsubstituted with at least one halogen Or a branched alkenyl or alkenyloxy group, wherein at least one of _-1 -CH ₂ - in the R ₁ and the R ₂ may be independently -O-, -CH=CH-, -C≡C-, - CF=CF-, -CH=CF-, Or -COO-substitution, provided that the heteroatoms are not directly connected to each other.

Preferably, the rings A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ are the same or different and each independently represents , , , , , , or The ring structure.

More preferably, the rings A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ are each independently represented , , , , , or The ring structure.

Preferably, Z ₁ , Z ₃ , Z ₄ and Z ₅ are the same or different and each independently represents -COO-, -CF ₂ O-, -CH ₂ O-, -OCH ₂ -, -CH ₂ CH ₂ -, -CF=CF-, -CH=CH-, -(CH ₂ ) ₄ -, -C ₂ F ₄ -, -(CF ₂ ) ₄ -, -OCF ₂ CF ₂ O-, -CF=CFCF ₂ O-, -C≡C- or single bond.

More preferably, Z ₁ , Z ₃ , Z ₄ and Z ₅ are the same or different and each independently represents -CF ₂ O-, -CH ₂ O-, -CH ₂ CH ₂ -, -CF=CF-, - CH=CH-, -CF=CFCF ₂ O-, -C≡C- or single bond.

Preferably, a represents 0 or 1, and b+c+d 3.

Preferably, the liquid crystal compound of the formula (I) is selected from the group consisting of: Wherein R ₁ and R _{2 are the} same or different and each independently represents H, —F, —Cl, —CN, a linear or branched alkane having 1 to 7 carbon atoms substituted or unsubstituted with at least one halogen; Or an alkoxy group, wherein at least one of _-1 -CH ₂ - in the R ₁ and the R ₂ may be independently -O-, -CH=CH-, -C≡C-, -CF=CF-, -CH=CF-, Or -COO-substitution, provided that the heteroatoms are not directly connected to each other.

Preferably, the liquid crystal composition comprises from 1 to 5 liquid crystal compounds of the formula (I).

More preferably, the liquid crystal composition comprises from 2 to 4 liquid crystal compounds of the formula (I).

The other mixed component of the liquid crystal composition of the present invention may be a conventional liquid crystal compound, that is, a compound which can form a liquid crystal phase in a pure state or in combination with other components. Some such compounds are mentioned, for example, in DE 1804894 and CN1158602A.

Preferably, the liquid crystal composition further comprises at least one liquid crystal compound of the formula (II):

Wherein R ₃ and R ₄ are the same or different and each independently represents -H, -F, -Cl, -CN, -NCS, -SCN, -OCN, -NCO, -OCH=CF ₂ , and has 1 to 20 a linear or branched alkyl or alkoxy group having one carbon atom substituted by at least one halogen or unsubstituted, or a linear or branched olefin having 2 to 20 carbon atoms substituted or unsubstituted with at least one halogen Or an alkenyloxy group, wherein at least one of the R ₃ and the R ₄ -CH ₂ - may be independently independently -O-, -S-, -SiH ₂ -, -CH=CH-, -C≡ C-, -CF=CF-, -CH=CF-, , -COO- or -OCO-, provided that the heteroatoms are not directly connected to each _{other; B 1, B 2, B} 3 and B ₄ are the same or different, each independently represent a , , , , 2,3-difluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2-fluoro-1, 4-phenylene, 2,6-difluoro-1,4-phenylene, 3,5-difluoro-1,4-phenylene, indane-2,5-diyl, acridine-1 , 4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, wherein One or two of the non-adjacent -CH ₂ - may be independently substituted by -O- or -S-, One or more H's may be independently replaced by F, which One or two non-adjacent -CH- of each may be independently replaced by N, One or two non-adjacent -CH ₂ - may be independently replaced by O, The above one or more H may be independently substituted by F; Y ₁ , Y ₂ and Y ₃ are the same or different, each independently representing -OCO-, -COO-, -CF ₂ O-, -CH ₂ O- , -OCH ₂ -, -CH ₂ CH ₂ -, -CF ₂ CH ₂ -, -CF=CF-, -CH=CH-, -CH(CH ₃ )CH ₂ -, -CH ₂ CH(CH ₃ ) -, -(CH ₂ ) ₃ O-, -O(CH ₂ ) ₃ -, -COS-, -SCO-, -CH=CF-, -C ₂ F ₄ -, -(CH ₂ ) ₄ -, - C ₄ F ₈ -, -OCF ₂ CF ₂ O-, -CF ₂ CF ₂ CF ₂ O-, -CH ₂ CH ₂ CF ₂ O-, -CH ₂ CF ₂ OCH ₂ -, -CH=CHCF ₂ O- _{, -CF 2 OCH = CH -,} - CF 2 OCF = CH -, - CF 2 OCH = CF -, - CF = CFCF 2 O -, - CF 2 OCF = CF -, - CH = CHCH 2 CH 2 -, -C ₂ H ₄ OCH ₂ -, -CH ₂ CH=CHCH ₂ -, -OCH ₂ CH ₂ CH ₂ -, -CF=CF-CF=CF-, -C≡C-CF=CF-, -C≡ C-CF=CF-C≡C-, -CF=CF-C≡C-CF=CF-, -C≡C-CF ₂ O-, -C≡C- or a single bond, wherein, in the Y ₁ And any one of Y ₂ -CH ₂ - may be independently substituted by -SiH ₂ -; m, n and p are the same or different, each independently representing 0, 1 or 2, when m is 2, two B are each the same or different from the Y ₁ and two _1; when n is 2 are each the same or different, and two two the Y ₂ B _2; when p is 2, two Two B ₃ and Y ₃ are each the same or different.

Preferably, the liquid crystal compound of the formula (II) is selected from the group consisting of:

Preferably, the compound of the formula (I) is used in an amount ranging from 5 to 50% by weight based on 100% by weight of the total weight of the liquid crystal composition, and the formula (II) The amount of the compound ranges from 50 to 95% by weight.

More preferably, the compound of the formula (I) is used in an amount ranging from 10 to 30% by weight based on 100% by weight of the total weight of the liquid crystal composition, and the compound of the formula (II) is used in an amount ranging from 70 to 90% by weight.

The invention will now be described in connection with specific embodiments. It is to be understood that the following examples are illustrative of the invention and are not intended to limit the invention. Other combinations and various modifications within the inventive concept can be made without departing from the spirit or scope of the invention.

For ease of expression, in the following examples, the group structure of the liquid crystal compound is represented by the codes listed in Table 1:

Take a compound of the following structural formula as an example:

The structural formula is represented by the code listed in Table 1, and can be expressed as: 3PUQUF.

[Example 1]

The synthetic method for preparing the compound HCLC-12 is as follows:

The specific synthesis steps are as follows:

(1) Synthesis of HCLC-12-2

21.8 g of propiconol was added to a 500 mL three-necked flask, and dissolved in 200 mL of dimethylformamide (DMF), and 8 g of 60 was added under a nitrogen atmosphere. After wt% sodium hydride (NaH), the mixture was heated to 60 ° C for 1 hour, cooled to 30 ° C, and 31.2 g of tetrafluorodibromoethane was added dropwise, and then reacted at room temperature (25 ± 3 ° C) for 12 hours. 200 mL of ethyl acetate and 200 mL of water were added, the aqueous layer was separated from the organic layer, and the aqueous layer was extracted with ethyl acetate (200 mL). The organic layer was combined and washed twice, then washed twice with brine and dried to give a crude product 38.5. g, crude column chromatography with petroleum ether to give 34 g of HCLC-12-2. Purity: 98.8%, yield 85.6%.

(2) Synthesis of HCLC-12-1

20 g of HCLC-12-2, 6 g of zinc powder and 100 mL of acetonitrile were placed in a 250 mL reaction flask, and the mixture was refluxed under nitrogen for 11 hours, cooled to room temperature (25 ± 3 ° C), suction filtered, and dried to give a crude product. The crude product was dissolved in petroleum ether, and subjected to column chromatography using petroleum ether, and dried to give 13.4 g of HCLC-12-1. Yield 89%, purity: 86.3%.

(3) Synthesis of HCLC-12

1.9 g of 60 wt% sodium hydride, 3.2 g of 2,3-difluoro-4-ethoxyphenol and 100 mL of DMF were added to a 250 mL reaction flask, and the mixture was heated to 60 ° C for 1 hour under nitrogen, and 6 g of HCLC-12- was added. The reaction was carried out at 1,60 ° C for 6 hours, 300 mL of water and 200 mL of ethyl acetate were added, washed with water, washed with brine, dried, concentrated, and purified by column chromatography with petroleum ether to obtain 8.4 g of colorless oil, then 10 mL The ethanol was recrystallized four times at -30 ° C to obtain 1.97 g of HCLC-12 as a colorless, transparent oil, purity: 99.7%, yield 25%.

_{1 H NMR (300MHz, CDCl 3} ) δ 7.50-7.21 (m, 2H), 6.94-6.76 (m, 2H), 6.55-6.60 (m, 2H), 4.09 (q, J = 11.8Hz, 2H), 2.69 -2.73 (m, 1H), 1.89-1.09 (m, 16H), 0.93-0.82 (m, 3H).

[Embodiment 2]

The synthetic method for preparing the compound HCLC-12K is as follows:

[4,4-Difluoro-(3,4,5-trifluorophenoxy)methyl]-3,5-difluorobenzeneboronic acid can be synthesized by a known method of the prior art (the synthesis method can be referred to the European Journal Of Organic Chemistry, 2008, V20 p3479-3487).

The specific synthetic steps of HCLC-12K are as follows:

(1) Synthesis of HCLC-12K-4

15 g of p-propylphenol and 150 mL of DMF were added to a 250 mL three-necked flask, dissolved, and 4.4 g of sodium hydride was added under a nitrogen atmosphere, the temperature was raised to 60 ° C for 1 hour, the temperature was lowered to 30 ° C, and tetrafluorodibromoethane 36 g was added dropwise. Thereafter, the reaction was carried out at room temperature (25 ± 3 ° C) for 12 hours. Add 200 mL of ethyl acetate and 200 mL of water. The aqueous layer and the organic layer were separated. The aqueous layer was extracted with 200 mL of ethyl acetate. The organic layer was combined, washed twice with water, then washed twice with brine and dried to give a crude product. 30 g of petroleum ether was subjected to crude column chromatography to give 22.5 g of HCLC-12K-4. Purity: 96.5%, yield 64.8%.

(2) Synthesis of HCLC-12K-3

22.5 g of HCLC-12K-4, 10 g of zinc powder and 150 mL of acetonitrile were added to a 250 mL reaction flask, and the mixture was refluxed under nitrogen for 11 hours, cooled to room temperature (25 ± 3 ° C), suction filtered, and dried to give a crude product. The crude product was dissolved in petroleum ether, and subjected to column chromatography, and then concentrated to give 9.6 g of HCLC-12K-3. Yield 62.3%, purity: 85.8%.

(3) Synthesis of HCLC-12K-2

Add 1 g of p-hydroxyphenylboronic acid, 43.5 g of 3-fluoro-4-iodobromobenzene, 30.5 g of anhydrous sodium carbonate, 144 mL of deionized water, 160 mL of toluene and 80 mL of absolute ethanol to a 1 L dry clean one-necked flask, and replace with argon gas. After evacuation, 0.5 g of Pd[P(Ph) ₃ ] _{4 was added} . The mixture was heated under reflux for 6 hours under an argon atmosphere. The reaction mixture was cooled and separated. Water was evaporated from 20 g of anhydrous sodium sulfate, and the organic phase was evaporated to dryness and then purified by column chromatography using 3:1 petroleum ether and ethyl acetate. The solvent was evaporated to dryness with EtOAc (EtOAc) (EtOAc). 82%.

(4) Synthesis of HCLC-12K-1

Add 6g of HCLC-12K-2 and 8g of [4,4-difluoro-(3,4,5-trifluorophenoxy)methyl]-3,5-difluorobenzene to a 250mL dry clean one-necked flask. Boric acid, 4.8 g of anhydrous sodium carbonate, 25 mL of deionized water, 100 mL of toluene and 25 mL of absolute ethanol were replaced by argon gas, and then 0.5 g of Pd[P(Ph) ₃ ] _{4 was added} . The mixture was heated under reflux for 12 hours under an argon atmosphere. The reaction mixture was cooled and separated. The organic phase was evaporated to dryness, and then purified by column chromatography using 3:1 petroleum ether and ethyl acetate. Dry solvent gave 11 g of a pale yellow solid. EtOAc (EtOAc)

(5) Synthesis of HCLC-12K

0.7 g of 60 wt% sodium hydride, 5 g of HCLC-12K-1, 50 mL of DMF was added to a 100 mL reaction flask, and the mixture was heated to 60 ° C for 1 hour under nitrogen, and 3.0 g of HCLC-12K-3 was added thereto, and reacted at 60 ° C for 1 hour, and water was added thereto. Extracted with ethyl acetate (200 mL), combined with all organics, washed with water, then washed with brine, dried and concentrated to give a crude product, eluted with 5:1 petroleum ether and ethyl acetate. The solvent was evaporated to dryness to give EtOAc (EtOAc: EtOAc)

¹ H NMR (300 MHz, CDCl ₃ ) δ 7.94 (dd, J =15.0, 10.1 Hz, 1H), 7.71 (dd, J =16.0, 3.0 Hz, 1H), 7.62-7.53 (m, 2H), 7.36-7.28 (m,,2H), 7.08-6.97 (m, 3H), 6.95-6.76 (m, 6H), 2.61 (t, J = 15.5 Hz, 2H), 1.74-1.55 (m, 2H), 0.94 (t, J = 13.2 Hz, 3H).

[Example 3]

The synthetic method for preparing the compound HCLC-12M is as follows:

The specific synthetic steps of HCLC-12M are as follows:

(1) Synthesis of HCLC-12M-1

4 g of p-bromophenol and 7.8 g of [4,4-difluoro-(3,4,5-trifluorophenoxy)methyl]-3,5-difluorophenylboronic acid were added to a 250 mL dry clean single-necked flask. 4.8 g of anhydrous sodium carbonate, 25 mL of deionized water, 100 mL of toluene and 25 mL of absolute ethanol were replaced by argon gas, and then 0.5 g of Pd[P(Ph) ₃ ] _{4 was added} . The mixture was heated under reflux for 12 hours under an argon atmosphere. The reaction mixture was cooled and separated. The organic phase was evaporated to dryness, and then purified by column chromatography using 3:1 petroleum ether and ethyl acetate. The solvent was dried to give 9.2 g (yield of pale yellow solid), and the crude product was recrystallized twice with 20 mL of anhydrous ethanol to give 8.1 g of white solid (HCLC-12M-1), purity: 99.6%, yield 87%.

(2) Synthesis of HCLC-12M

0.7 g of 60 wt% sodium hydride was added to a 100 mL reaction flask. 5g HCLC-12M-1 and 50mL DMF, heated to 60 ° C under nitrogen atmosphere for 1 hour, add 2.6g HCLC-12K-3, react at 60 ° C for 1 hour, add water 100mL, ethyl acetate 200mL extraction, first wash, then After washing with brine, drying and concentrating, the column chromatography was carried out with 5:1 petroleum ether and ethyl acetate, and the solvent was evaporated to dryness to give 6.9 g of colorless oil. It was recrystallized four times with 20 mL of ethanol to give a white solid 29 g (HCLC-12M), purity: 99.6%, yield 39%.

_{^{1 H NMR (300MHz, CDCl 3}} ) δ 7.62-7.53 (m, 2H), 7.29-7.35 (m, 2H), 7.06-6.97 (m, 2H), 6.93-6.76 (m, 6H), 2.61 (t, J = 15.6 Hz, 2H), 1.74-1.55 (m, 2H), 0.94 (t, J = 13.2 Hz, 3H).

[Example 4]

The synthesis method for preparing the compound HCLC-12N is as follows:

In the synthesis of HCLC-12N-1, according to the method of synthesizing HCLC-12M-1, 3-fluoro-4-bromophenol was used instead of p-bromophenol, and then the white solid HCLC-12N was obtained according to the synthesis method of compound HCLC-12M. .

_{^{1 H NMR (300MHz, CDCl 3}} ) δ 7.62-7.57 (m, 1H), 7.27-7.09 (m, 5H), 6.95-6.83 (m, 4H), 6.53-6.62 (m, 1H), 2.62 (t, J = 15.6 Hz, 2H), 1.68 - 1.55 (m, 2H), 0.93 (t, J = 13.2 Hz, 3H).

The following Example 5 is a performance test result of the liquid crystal composition of the present invention: the abbreviated code of the test parameters in the following examples is as follows:

[Example 5]

Table 2 shows the liquid crystal compositions formulated with HCLC-12N, HCLC-12K and HCLC-12M and the corresponding parameters obtained:

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the patent application and the patent specification of the present invention are It is still within the scope of the invention patent.

Claims (10)

A liquid crystal compound having the structure of the formula (I): Wherein R ₁ and R ₂ are the same or different and each independently represents -H, -F, -Cl, -CN, -NCS, -SCN, -OCN, -NCO, a linear or branched alkyl or alkoxy group having 1 to 20 carbon atoms substituted or unsubstituted with at least one halogen, a linear chain having 2 to 20 carbon atoms substituted or unsubstituted with at least one halogen Or a branched alkenyl or alkenyloxy group, wherein at least one of _-1 -CH ₂ - in R ₁ and R ₂ may be independently independently taken up by -O-, -S-, -SiH ₂ -, -CH=CH -, -C≡C-, -CF=CF-, -CH=CF-, , -COO- or -OCO-substitution, provided that the heteroatoms are not directly linked to each other; the rings A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ are the same or different and each independently represents or Alternatively, the cyclic structure may also conform to (a) below: (a) one or more hydrogen atoms in the cyclic structure may be independently independently -D, -F, -Cl, -CN , -CF ₃ , -OCF ₃ , -CH ₂ F, -OCH ₂ F, -CF ₂ H, -OCF ₂ H, -OCH ₃ or -CH ₃ substituted; Z ₁ , Z ₃ , Z ₄ and Z ₅ are The same or different, each independently represents a single bond, -COO-, -CF ₂ O-, -CH ₂ O-, -OCH ₂ -, -CH ₂ CH ₂ -, -CF ₂ CH ₂ -, -CF=CF -, -CH=CH-, -CH=CF-, -C ₂ F ₄ -, -(CH ₂ ) ₄ -, -(CF ₂ ) ₄ -, -OCF ₂ CF ₂ O-, -CF ₂ CF ₂ CF ₂ O-, -CH ₂ CH ₂ CF ₂ O-, -OCH ₂ CF ₂ O-, -CH ₂ CF ₂ OCH ₂ -, -CH=CHCF ₂ O-, -CF ₂ OCH=CH-, -CF ₂ OCF=CH-, -CF ₂ OCH=CF-, -CF=CFCF ₂ O-, -CF ₂ OCF=CF-, -CH=CHCH ₂ CH ₂ -, -CH ₂ CH=CHCH ₂ -, -C ₂ H ₄ OCH ₂ -, -OCH ₂ CH ₂ CH ₂ -, -CF=CF=CF=CF-, -C≡C-CF=CF-, -C≡C-CF=CF-C≡C-, -C≡C-, -CF=CF-C≡C-CF=CF- or -C≡C-CF ₂ O-; a represents 0 or 1, and b, c and d are the same or different and are independently represents 0, 1 or 2, when b is 2, two Z ₃ and two A ₄ are each the same or different; when c is 2, two Z ₄ Two A ₅ are each the same or different; when d is 2, two Z ₅ and A ₆ are each two identical or different, with the proviso that when the ring A ₂ and A ₃ When a+b+c+d is not equal to zero. The liquid crystal compound according to claim 1, wherein a represents 0 or 1 and b+c+d 3. The liquid crystal compound according to any one of claims 1 to 2, wherein the liquid crystal compound is selected from the group consisting of: Wherein R ₁ and R _{2 are the} same or different and each independently represents H, —F, —Cl, —CN, a linear or branched alkane having 1 to 7 carbon atoms substituted or unsubstituted with at least one halogen; Or an alkoxy group, wherein at least one of _-1 -CH ₂ - in the R ₁ and the R ₂ may be independently -O-, -CH=CH-, -C≡C-, -CF=CF-, -CH=CF-, Or -COO- substitution, provided that the heteroatoms are not directly connected to each other. A liquid crystal composition comprising at least one liquid crystal compound according to any one of claims 1 to 3. The liquid crystal composition according to claim 4, wherein the liquid crystal composition comprises one to five liquid crystal compounds according to any one of claims 1 to 3. The liquid crystal composition according to claim 4, which further comprises at least one liquid crystal compound of the formula (II): Wherein R ₃ and R ₄ are the same or different and each independently represents -H, -F, -Cl, -CN, -NCS, -SCN, -OCN, -NCO, -OCH=CF ₂ , and has 1 to 20 a linear or branched alkyl or alkoxy group having one carbon atom substituted by at least one halogen or unsubstituted, or a linear or branched olefin having 2 to 20 carbon atoms substituted or unsubstituted with at least one halogen Or an alkenyloxy group, wherein at least one of the R ₃ and the R ₄ -CH ₂ - may be independently independently -O-, -S-, -SiH ₂ -, -CH=CH-, -C≡ C-, -CF=CF-, -CH=CF-, , -COO- or -OCO-, provided that the heteroatoms are not directly connected to each _{other; B 1, B 2, B} 3 and B ₄ are the same or different, each independently represent a , , , , 2,3-difluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2-fluoro-1, 4-phenylene, 2,6-difluoro-1,4-phenylene, 3,5-difluoro-1,4-phenylene, indane-2,5-diyl, acridine-1 , 4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, wherein One or two of the non-adjacent -CH ₂ - may be independently substituted by -O- or -S-, One or more H's may be independently replaced by F, which One or two non-adjacent -CH- of each may be independently replaced by N, One or two non-adjacent -CH ₂ - may be independently replaced by O, The above one or more H may be independently substituted by F; Y ₁ , Y ₂ and Y ₃ are the same or different, each independently representing -OCO-, -COO-, -CF ₂ O-, -CH ₂ O- , -OCH ₂ -, -CH ₂ CH ₂ -, -CF ₂ CH ₂ -, -CF=CF-, -CH=CH-, -CH(CH ₃ )CH ₂ -, -CH ₂ CH(CH ₃ ) -, -(CH ₂ ) ₃ O-, -O(CH ₂ ) ₃ -, -COS-, -SCO-, -CH=CF-, -C ₂ F ₄ -, -(CH ₂ ) ₄ -, - C ₄ F ₈ -, -OCF ₂ CF ₂ O-, -CF ₂ CF ₂ CF ₂ O-, -CH ₂ CH ₂ CF ₂ O-, -CH ₂ CF ₂ OCH ₂ -, -CH=CHCF ₂ O- _{, -CF 2 OCH = CH -,} - CF 2 OCF = CH -, - CF 2 OCH = CF -, - CF = CFCF 2 O -, - CF 2 OCF = CF -, - CH = CHCH 2 CH 2 -, -C ₂ H ₄ OCH ₂ -, -CH ₂ CH=CHCH ₂ -, -OCH ₂ CH ₂ CH ₂ -, -CF=CF-CF=CF-, -C≡C-CF=CF-, -C≡ C-CF=CF-C≡C-, -CF=CF-C≡C-CF=CF-, -C≡C-CF ₂ O-, -C≡C- or a single bond, wherein, in the Y ₁ And any one of Y ₂ -CH ₂ - may be independently substituted by -SiH ₂ -; m, n and p are the same or different, each independently representing 0, 1 or 2, when m is 2, two B are each the same or different from the Y ₁ and two _1; when n is 2 are each the same or different, and two two the Y ₂ B _2; when p is 2, two Two B ₃ and Y ₃ are each the same or different. The liquid crystal composition according to claim 6, wherein the liquid crystal compound of the formula (II) is selected from the group consisting of: The liquid crystal composition according to claim 6 or 7, wherein the liquid crystal compound of the formula (I) is used in an amount ranging from 5 to 50% by weight based on 100% by weight of the total weight of the liquid crystal composition, and the formula (II) The amount of the liquid crystal compound ranges from 50 to 95% by weight. The liquid crystal composition according to claim 8, wherein the liquid crystal compound of the formula (I) is used in an amount ranging from 10 to 30% by weight based on 100% by weight of the total of the liquid crystal composition, and the liquid crystal of the formula (II) The amount of the compound ranges from 70 to 90% by weight. A liquid crystal display comprising the liquid crystal composition according to any one of claims 4 to 9.